16
EPSON
E0C6006 TECHNICAL MANUAL
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Input Ports)
4.4.3 Mask option
An internal pull-up resistor can be selected for each of the eight bits of the input ports (K00–K03, K10–
K13). Having selected "pull-up resistor disabled", take care that the input does not float. Select "pull-up
resistor enabled" for input ports that are not being used.
4.4.4 I/O memory of input port
Table 4.4.4.1 shows the I/O addresses and the control bits for the input port.
Table 4.4.4.1 Control bits of input port
Address
Comment
D3
D2
Register
D1
D0
Name
Init
∗
1
1
0
0FAH
K03
K02
K01
K00
R
K03
K02
K01
K00
–
∗
2
–
∗
2
–
∗
2
–
∗
2
High
High
High
High
Low
Low
Low
Low
K0 input port data
0FBH
K13
K12
K11
K10
R
K13
K12
K11
K10
–
∗
2
–
∗
2
–
∗
2
–
∗
2
High
High
High
High
Low
Low
Low
Low
K1 input port data
0F2H
REMC
EIREM
EIK1
EIK0
R/W
REMC
EIREM
EIK1
EIK0
1
0
0
0
On
Enable
Enable
Enable
Off
Mask
Mask
Mask
REM carrier generation on/off
Interrupt mask register (REM)
Interrupt mask register (K10–K13)
Interrupt mask register (K00–K03)
0F0H
REMSO
IREM
IK1
IK0
R/W
R
REMSO
IREM
∗
4
IK1
∗
4
IK0
∗
4
0
–
∗
5
0
0
On
Yes
Yes
Yes
Off
No
No
No
Forced REM output (on/off)
Interrupt factor flag (REM)
Interrupt factor flag (K10–K13)
Interrupt factor flag (K00–K03)
∗
1
∗
2
Initial value at initial reset
Not set in the circuit
∗
5 Undefined
∗
3
∗
4
Always "0" being read
Reset (0) immediately after being read
K00–K03: Input port data (0FAH)
K10–K13: Input port data (0FBH)
The input data of the input port terminals can be read with these registers.
When "1" is read: High level
When "0" is read: Low level
Writing: Invalid
The value read is "1" when the terminal voltage of the input port (K00–K03, K10–K13) goes high (V
DD
),
and "0" when the voltage goes low (V
SS
). These bits are reading only, so writing cannot be done.
EIK0, EIK1: Interrupt mask registers (0F2H•D0, D1)
Masking the interrupt of the input port terminal groups can be done with these registers.
When "1" is written: Enabled
When "0" is written: Masked
Reading: Valid
With these registers, masking of the input port bits can be done for each of the four-bit terminal groups.
At initial reset, these registers are all set to "0".